Ethyl n-cyclohexyl n-propargyl-thiolcarbamate as a herbicide

ABSTRACT

New and valuable substituted thiolcarbamates having the formula IN WHICH R1 denotes a propargyl, cyanomethyl, Beta -cyanoethyl or Beta -chloro- Beta -cyanoethyl radical and R2 has the same meanings as R1, R1 and R2 being identical or different, and R2 may also denote a phenyl or cyclohexyl radical or an aliphatic radical having not more than six carbon atoms which may bear hydroxyl, chloro or thiocyano, lower alkoxythioether or lower alkylthioether groups as substituents and R3 denotes an aliphatic radical which may be substituted by halogen atoms. These compounds are effective herbicidal active ingredients which are particularly suitable for controlling unwanted grassy plants while leaving crop plants undamaged.

United States Patent Kiehs et al.

[ 1 Aug. 29, 1972 [54] ETHYL N-CYCLOHEXYL N- PROPARGYL-THIOLCARBAMATE AS A HERBICIDE [72] Inventors: Karl Kiehs, 4 Sudermannstrasse,

6700 Ludwigshafen; Karl-Heinz Koenig, 8a Pierstrasse, 6710 Frankenthal; Adolf Fischer, 43

Speyererstrasse, 6704 Mutterstadt,

all of Germany [22] Filed: March 27, 1969 [21] Appl. No.: 811,226

[52] U.S. Cl ..260/455 A, 260/454, 71/100 [51] Int. Cl ..C07c 155/08 [58] Field of Search ..260/455 A; 71/100 [56] References Cited UNITED STATES PATENTS 2,901,499 8/ 1959 Tilles et al. ..7 1/ 100 3,151,119 9/1964 Grislcy et al ..260/455 3,175,897 3/1965 Tilles et al. ..71/100 3,235 ,368 2/1966 Surgant ..260/455 3,298,817 1/1967 Tilles ..260/455 3,305,576 2/1967 DAmico et al. ..71/100 3,268,524 8/1966 Moore ..260/563 OTHER PUBLICATIONS Tilles, II 'lhiolcarb'amates, Prep. & Mo]. Refractions," (1959) CA 53, pp. 16,955- 16,960 (1959) Primary Examiner-Jewis Gotts Assistant Examiner-G. Hollrah Attorney-Johnston, Root, OKeeffe, Keil, Thompson & Shurtleff ABSTRACT New and valuable substituted thiolcarbamates having the formula in which R denotes a propargyl, cyanomethyl, B- cyanoethyl or B-chloro-B-cyanoethyl radical and R has the same meanings as R, R and R being identical or different, and R may also denote a phenyl or cyclohexyl radical or an aliphatic radical having not more than six carbon atoms which may bear hydroxyl, chloro or thiocyano, lower alkoxythioether or lower alkylthioether groups as substituents and R denotes an aliphatic radical which may be substituted by halogen atoms. These compounds are effective herbicidal active ingredients which are particularly suitable for controlling unwanted grassy plants while leaving crop plants undamaged.

1 Claim, No Drawings ETHYL N-CYCLOHEXYL N-PROPARGYL- THIOLCARBAMATE AS A HERBICIDE The present invention relates to substituted thiolcarbamates and herbicides containing them.

It is known to use n-propyl-N-ethyl-N-butylthiolcarbamate and ethyl-N-ethyl-N-cyclohexylthiolcarbamate as herbicides (US. Pat. No. 3,175,897); their action is, however, not satisfactory.

An object of the invention is new and valuable substituted thiolcarbamates. A further object of the invention is a process for controlling unwanted plants with new and valuable substituted thiolcarbamates. Yet another object of the invention is the control of unwanted plants without damaging crop plants. These and other objects of the invention are achieved by substituted thiolcarbamates having the formula in which R denotes a propargyl, cyanomethyl, ,B- cyanoethyl or fl-chloro-B-cyanoethyl radical and R has the same meanings as R, R and R being identical or different, and R may also denote a phenyl or cyclohexyl radical or an aliphatic radical having not more than six carbon atoms (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-pentyl, allyl, methallyl, isobutynyl, 3-methylbutyn(l)yl-(3)) which may bear hydroxyl, chloro or thiocyano, lower alkoxy (methoxy, ethoxy, propoxy) or alkyl (methyl, ethyl, propyl, isopropyl, butyl, isobutyl) thioether groups as substituents, and R denotes an aliphatic (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secbutyl, tert-butyl, allyl, methallyl, isobutynyl, 3-methylbutyn-(1)yl(3)) radical which may be substituted by one or more than one halogen atom (chlorine, bromine).

The new active ingredients may be prepared by reacting N,N-disubstituted carbamic acid chlorides with mercaptans in the presence of acid-binding agents or with the alkali metal or alkaline earth metal salts of mercaptans or by reacting compounds having the formula in which X denotes halogen and R has the meanings given above with the corresponding amines.

EXAMPLE 1 N-propyl-N-propyl-N-B- ture of 50 C. As residue, 10.3 parts of the product is obtained as a water oil; n 1.4912.

EXAMPLE 2 Preparation of ethyl-N-cyclohexyl-N-propargylthiolcarbamate Eighteen parts by weight of thioethyl chloroformate is dripped, at to C, into a mixture of 15 parts by weight of triethylamine, 20 parts by weight of N- cyclohexyl-N-propargylamine and 120 parts by weight of benzene. The mixture is boiled under reflux for two hours and then decomposed with water. The solution is then washed with dilute sulfuric acid, dried and distilled. The end product is obtained in this manner in a yield of percent of the theory; boiling point at 0.01 mm=ll7to 119C.

Examples of active ingredients prepared in this way are as follows:

n-propyl-N-methyl-N-B-cyanoethylthiolcarbam ate 1 .4995 n-propyl-N-propyl-N-cyanomethylthiolcarbam ate 1 .4 909 n-propyl-N-propyl-N-( B-chloro-fl-cyanoethyl thiolcarbamate l .4 962 n-propyl-N-isopropyl-N-B cyanoethylthiolcarbamate 1.4937 n-propyl-N-butyl-N-B-cyanoethylthiolcarbamate l .4 89 l n-propyl-N-butyl-N-cyanomethylthiolcarbamate l .4 8 8 8 n-propyl-N-n-hexyl-N-B-cyanoethylthiolcarbamate l .4 8 5 8 n-propyl-N-allyl-N-fl-cyanoethylthiolcarb amate l .5 040 n-propyl-N-methoxyethyl-N-B- cyanoethylthiolcarbamate 1.4923 n-pro pyl-N-rnethoxyethyl-N- cyanomethylthiolcarbamate l .4 898 n-propyl-N ,N-bis-B-cyanoethylthiolcarbamate 1.5 08 8 n-propyl-N-phenyl-N-B-cyanoethylthiolcarbam ate 1 .5 490 n-propyl-N-hydroxyethyl-N-B- cyanoethylthiolcarbamate l .5 109 ethyl-N-methyl-N-B-cyanoethylthiolcarbamate l .5 030 ethyl-N-propyl-N-cyanomethylthiolcarbamate l .493 7 ethyl-N-isopropyl-N-Bcyanoethylthiolcarbam ate 1 .4 963 ethyl-N-n-butyl-N-cyanomethylthiolcarbamate l .4 908 ethyl-N-n-butyl-N-fl-cyanoethylthiolcarbamate l .49 l 8 ethyl-N-n-hexyl-N-B-cyanoethylthiolcarbamate 1.4 8 7 3 ethyl-N-methoxyethyl-N-cyanomethylcarb amate l .4 94 l ethyl-N-methoxyethyl-N-ficyanoethylthiolcarbamate l .4 95 5 ethyl-N,N-bis-B-cyanoethylthiolcarbamate l .5 l 27 ethyl-N-cyclohexyl-N-c yanomethylthiolcarbam ate 1 .5 l 63 ethyl-N-cyclohexyl-N-B-cyanoethylthiolcarbamate l .5 n-propyl-N-ethyl-N-( butyn( 2 )yl )thiolcarbamate b.p. (93 mm) 9l92C n-propyl-N-propyl-N-B-cyanoethylthiolcarbamate l .49 l 2 n-propyl-N-fi-chloroeth yl-N -ficyanoethylthiolcarbamate 1.5131 n-propyl-N-(-n-butyl )-N-(propargyl)thiolcarbamate b.p. (0.1 mm) 82-83C The agents for controlling plant growth according to the invention may be applied as solutions, emulsion, suspensions or dusts. The form of application depends entirely on the purpose for which the agents are being used; in any case it should ensure a fine distribution of the active ingredient.

For the preparation of solutions to be sprayed direct hydrocarbons such as tetrahydronaphthalene and alkylated naphthalenes are suitable.

Aqueous formulations may be prepared from emulsion concentrates, pastes or wettable powders by adding water. To prepare emulsions the ingredients as such or dissolved in a solvent maybe homogenized in water or organic solvents by means of wetting or dispersing agents such as ethylene oxide adducts. Concentrates which are suitable for dilution with water may be prepared from active ingredient, emulsifying or dispersing agent and possibly solvent.

EXAMPLE 3 In a greenhouse, sandy soil is filled into pots and sown with seeds of beet (Beta vulgaris), wheat (Triticum vulgare), barley (Hordeum vulgare), rye (Secale cereale), oats (Avena sativa), annual meadow grass (Poa annua), perennial ryegrass (Lolium perenne) and slender foxtail (Alopecurus myosuroides). The soil prepared in this manner is then treated with 4 kg per hectare of n-propyl-N-propyl-N-B-cyanoethylthiolcarbamate (I) and, for comparison, with 4 kg per hectare of n-propyl-N-ethyl-N-n-butylthiolcarbamate (II), these amounts of the active ingredients each being emulsified in 500 liters of water per hectare. After six weeks it is ascertained that I has superior selectivity in cereals.

In a greenhouse the plants wheat (Triticum vulgare), barley (Mordeum vulgare), rye (Secale cereale), oats (Avena sativa), garden cress (Lepidium sativum), mustard (Sinapis alba), wild mustard (Sinapis arvensis) and Russian vetch (Vicia villosa) are treated at a growth height of 5 to 10 cm with 4 kg per hectare of npropyl-N-prpyl-N-B-cyanoethylthiolcarbamate emulsified in 00 liters of water per hectare.

After three weeks the following results are ascertained:

Wheat 0-10 Barley Rye l0-20 Oats 30 Garden cress 100 Mustard 50 Wild mustard 50-60 Russian vetch 100 0 no action 100 total destruction EXAMPLE 5 An experimental area is sown with annual meadow grass (Poa annua), perennial ryegrass (Lolium perenne), slender foxtail (Alopecurus myasuroides), orchard grass (Dactylis glomerata), browntop (Agrostis vulgaris), wild mustard (Sinapis arvensis) and Russian vetch (Vicia villosa) and treated on the same day with 10 kg per hectare of n-propyl-N-propyl-N-B- cyanoethylthiolcarbamate emulsified in 500 liters of water per hectare. After three to four weeks almost all the plants are comple t ly A plot with wild mustard (Sinapis arvensis), Russian vetch (Vicia villosa), annual meadow grass (Poa annua), perennial ryegrass (Lolium perenne) and slender foxtail (Alopecurus myosuroides) growing on it is sprayed, at a growth height of the plants of 3 to 8 cm, with 10 kg per hectare of n-propyl-N-propyl-N-B- cyanoethylthiolcarbamate dispersed in 500 liters of water per hectare. After two to three weeks almost all the plants are completely withered.

EXAMPLE 7 Loamy sandy soil is filled into pots and sown with seeds of Indian corn (Zea mays), beet (Beta vulgaris), cabbage (Brassica oleracea var. vulgaris), annual meadow grass (Poa annua), wild oats (Avena fatua), barnyard grass (Echinochloa crus-galli), green foxtail (Setaria viridis) and large crabgrass (Digitaria sanguinalis). The soil prepared in this manner is then treated with 3 kg per hectare of ethyl-N-propargyl-N- cyclohexylthiolcarbamate (l) and, for comparison, with 3 kg per hectare of ethyl-N-ethyl-N-cyclohexylthiol-carbamate (II), these amounts of the active ingredients each being dispersed in 500 liters of water per hectare. After four to five weeks it is ascertained that I has superior compatibility with Indian corn and cabbage.

A 2 m plot with cabbage (Brassica oleracea var. vulgaris), beet(Beta vulgaris), annual meadow grass (Poa annua), wild oats (Avena fatua) and barnyard grass (Echinochloa crus-galli) growing on it is treated with 3 kg per hectare of ethyl-N-propargyl-N-cyclohexylthiolcarbamate (I) dispersed in 500 liters of water per hectare. After three to four weeks it is ascertained that the grassy weeds are almost completely withered whereas beet and cabbage undergo only slight growth retardation which is overcome later on.

The compounds listed after Example 2 have the same good biological action as I in Examples 3 to 8.

We claim:

1. Ethyl-N-cyclohexyl-N-propargylthiolcarbamate.

- UNRTEB STATES PATENT @FFEQE teiirimit or Dated August 29. 1972 Patent No. 5,687,997

Inventor) Karl Kiehs, Karl-Heinz Koenig, and Adolf Fischer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

First page, left-hand column, tenth line, insert 75 3 Assignee: Badische Anilin- 8c Soda-Fabrik Akztiengesellschaft, Ludwigshafen Rhein, Germany line thirteen, insert [3O Foreign Application Priority Date April 26, 1968 Germany P 17 68 296.1

Column 2, line 2, 1 "water oil" should read water-clear oil Column 3, line 58, "(Mordeum vulgare)" should read (Hordeum vulgare) Signed and sealed this 15th day of January 197E.

( SEAL) Attest:

EDWARD MQFLETC HER, JR. I RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents 

